Newcastle disease virus (NDV) is capable of causing infection to a variety of poultries, while it has no pathogenicity to human. NDV, which belongs to the genus of Avulavirus in the Paramyxoviridae family, is a single-negative-stranded RNA virus, and it contains six independent transcription and coding units including nuclear protein (NP), phosphoprotein (P), matrix protein (M), fusion protein (F), hemagglutinin neuraminidase protein (HN) and large polymerase protein (L). A minimum infection unit of NDV is ribonucleoprotein composite, where genomic RNA, NP, P and L of NDV are assembled together into the infective ribonucleoprotein composite, thereby initiating preliminary transcription of the RNA as well as translation and synthesis of virus protein to generate infective progeny virus.
Reverse genetics is named with respect to classic genetics. Research strategy originating from genotype to phenotype of an organism, and various research techniques related thereto are generally named as reverse genetic techniques. The reverse genetic technique related to the RNA virus means that cloning for the infective molecule of the RNA virus were built in vitro, in which genomic RNA of the virus is reversedly transcribed into cDNA and various in vitro transformations, e.g., gene mutation, gene deletion, gene insertion, gene substitution, gene complementation and etc., are performed on the genome of the RNA virus at a DNA level, where such transformations are also called as “virus rescue”.
Under the catalysis of α1,3galactosyltransferase (α1,3GT), glycosyl of uridine diphosphate galactose is transferred to N-acetyl glucosamine residue of chain of glycolipid and glycoprotein to form a α-galactosidase antigen (α-Gal antigen). α-Gal or Galα1-3Galβ1-4GlcNAc-R is a special carbohydrate structure, and α-galactosyl residue at its end is a natural specific recognition site for antigen since galactoses have to form α-connection at 1 and 3 sites therebetween.